Apparatus for mechanically and electrically connecting conductors carrying high frequency currents



Dec. 24, 1940. w, pupp 2,226,479

APPARATUS FOR MECHANICALLY AND ELECTRICALLY CONNECTING CONDUCTORS CARRYING HIGH FREQUENCY CURRENTS Filed Jan. 22, 1958 2 Sheets-Sheet 1 w? I a I 2 Mm 9 (Zn/maxi Dec. 24, 1940. w pupp 2,226,479

APPARATUS FOR MECHANICALLY AND ELECTRIOALLY couuac'rmc CONDUCTORS CARRYING HIGH FREQUENCY CURRENTS Filed Jan. 22, 1938 2 Sheets-Sheet 2 Patented Dec. 24, 1940 y I fREN rs Wolfgang Pupp Berlin -Kopenick, Germany, as-

, signer to'Julius-Pintsch Kommanditgesellschaft Application 1311mm, 193s, Serial No. 186,454

I In Germany February 8, 1937 This invention relates to ap aratus'frdi mechanically and electrically connecting conductors carrying high frequency, currents, and, con- 5 cer'ns'in particular apparatus for transmitting ergy-Ttransmittingfcables) [such as. are empl oyed',f for example; between oscillation generf ators and loadingresistances. The primary object of the present invention is to provide apparatus by means of which it is possible, to form a .mechanicaland electrical connection between two members carrying high frequency energy and to reduce the influence of contact resistance between these members.

The present inventionprovides apparatus for mechanically and electrically connecting conductors carrying high frequency current, in par-. ticular energy-transmitting cables, comprisirw.

. a member connecting points which are located at nodes of the current flowing through the 35 example by oxidation of the metal parts in ultra-short wave apparatus which is frequently located in the open air, or by loose contacts, is completely eliminated.

40 In a particular'example of carrying the present invention into eifect which relates to concentric energy-transmitting cables having a central conductor, the bore of the tuning member slides over the central conductor of the energytran'smitting cable, while the outer surface of the member slides inside the outer conductor of t the cable, the length of the member being equal at least to one quarter of the operating wave length. v

50 If the wave length employed with such an arrangement is not a fixed quantity, the currents flowing at the junction of the tuning member and thecable are still considerably smaller. than they would'be if the member was not tuned. If,

55 however, the wave; length is a fixed quantity the oscillation energy of ultra-high frequency (en-= system, preferably a concentric energy-transof contact resistances, which maybe formed, for

I to a plurality: of radiating systems;

current flowing at the said junction when tuned to resonance isgcompletely reduced to zero.

According to a further embodiment of the present invention the elasticity of the wall of the tuning ember is such that the wall adapts 5 itself to the shape of the ,energy-transmitting cable. No additional component parts, such as contact springs, tightening wedges and the like, are required for this purpose, but the wall of the memberis provided with a plurality of longitu- 10 dinal slots, six being a suitable numbera -fl-lhe spring action of the slottedwall extends overa length which is considerably greater than the diameter of the memberjand the contact points are located at the ends of the leai springs thus 15 formed, so that efficient movement of the tuning member can be effected. I i

In order that, the. present invention maybe clearly understoodspecific embodiments thereof will be described, by way of example, with refer-L enc'eito the accompanying drawings, but it will be understood that the invention is in nowav restricted to the specific details given below and that many modifications of the said detailsmay be eiiected withinthe scope of the appended claims. i

In the drawings: I

Figure 1 is a diagram showing the application" of the present invention. to a parallel conductor a cable; j I i v l Figure 2 is a sectional elevation of a concentric energy-transmitting cable tunedby a meme ber constructed in accordance withthe present invention; r

Figure 3 is a sectionalelevation of a concentric energy-transmitting cable tuned in accordance with the present invention and connected and Figure 4 is a sectional view of a concentric enorgy-transmitting cable provided with a tuning 40 member of variable length.

Referring to Figure 1, a parallel conductor cable (Lecher wire) I is connected to a high frequency electric generator la. This cable is tuned by means of a short-circuiting loop 2, the limbs of which are of the length M4 along the axis of the cable, where A is the wave-length of the transmitted current. The limbs are preferably constructed in the form of tubes which slide over'the two conductors. In this manner the current flowing between the short circuiting loop and the energy-transmitting cable (at 3) is reduced to zero. I

Figure 2 shows a, further example of the present, invention, in which a concentric cable .comprises an outer conductor 4 and a central conductor 5. An oscillation generator is connected to the cable at 6. The tuning member I is constructed in the form of a piston the length of which is M4. .The outer conductor H and the inner conductor ltiof the member 1 are electrically connected together, for exam ple, by soldering or by constructing the piston in a single piece. The parts 10 and H are provided with slots 72 in order to increase the spring action. The sliding of the piston in the direction of the axis may be effected in various ways, a simple manner being with the aid of a handle 8 projecting through a slot in the outer conductor 4. In particular, the piston may be moved through micrometer action by which the position can accurately and uniformly be varied, and adjusting mechanism can be provided with a scale divided into wave lengths or frequencies.

In the diagram shown in Figure 3 the present invention is applied to an energy-transmitting cable connected to a plurality of radiating systems, such as are fully described in United States of America patent application Serial No. 129,218. The outer conductor 4 and the inner conductor 5 are connected to a source of high frequency energy which is radiated through the individual radiating systems 9 which are connected to the energy-transmitting cable by means of gaps therein. A tuning piston .1 having a length of M4 is again provided for tuning the cable. As is shown in this example, it is not essentialthat the parts H and 70 should abut directly against the outer conductor and the inner conductor re-' spectively of the energy-transmitting cable, because the contact resistance between the tuning piston and the energy-transmitting cable is negligible owing to the fact that there is no current :iowing at the junction of the cable and the pis- It may be desirable when the .operating wave length of the circuit is not of fixed value to provide a set of tuning members of various sizes,

or to render the length of the tuning member variable. It is thus possible to vary the efiective lengths of the tuning piston in contact with the inner conductor and with the outer conductor either separately or simultaneously. A constructional example of this embodiment of the present invention in which the effective lengths may be varied simultaneously is shown in Figure 4. The outer conductor 4 and the inner conductor 5 of the energy-transmitting cable are connected to a source of high frequency energy. The tuning member 82 is provided with tubular component parts l3 and 14 which extend into flexible parts Ba and Ma, these being electrically conductive at least along the surfaces. The flexible parts l3a and Ma are connected to metal rings l5 and it, which are rigidly connected together by ceramic parts'23- of either disc or rod formation. The member I2 is provided with a tubular extension 24 having a screw thread along the outer surface. The distance of the rings I5 and Hi from the part l2 may be reduced by turning a nut 25 which engages the screw threaded extension 24, since the ceramic parts 23 are connectedto parts 21, 28 associated with the nut 25 by rods 26. The arrangement is such that the nut 25 may be turned without the rods 26 being rotated because the part 21 of the nut 25 rotatably engages the ring 28 connected to the rods 26.

The present invention is not limited to the examples described and illustrated, and may be applied, for example, in all cases where it is de- The invention may be employed with considerable advantage with the apparatus described and claimed in United States of America patent application Serial No. 129,218, and in particular in combination with the valves described and claimed in United States of America patent specification No. 2,128,233 and modifications thereof.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

1. Apparatus for tuning conductors carrying high frequency currents, in particular energytransmitting cables, comprising a connecting member which short-circuits said conductors at points located at nodes of the current flowing through the conductors, said connecting member being of a length along the axis of the conductors equal to at least one-quarter of the operating wave-length of the current flowing through said conductors.

2. Apparatus for tuning concentric energy transmitting cables having an outer conductor and a central conductor, comprising a hollow cylindrical member which is open at one end and which short-circuits the outer and central conductors of the cable at points located at nodes of the current flowing through said conductors, the said memberbeing of a length along the axis of the conductor equal at least to one quarter of the operating wave-length of the current flowing through saidv conductors.

3. Apparatus for tuning concentric energytransmitting cables having central conductors, comprising in combination a hollow cylindrical member which is open at one end and which short-circuits the conductors of the cable, the said member being of a length along the axis of the conductors equal at least to one quarter of the operating wave-length, and a plurality of longitudinal slots in the surface of the said memand which short-circuits the outer and central conductors of the cable at points located at nodes of the current flowing through said conductors, the said member being of a length along the axis of the conductors equal .at least to one quarter of the operating wave-length, and means for varying the position of the said member along the axis of said conductors.

5. Apparatus for tuning concentric energytransmitting cables having central conductors, comprising in combination a hollow cylindrical member which is open at one end and which short-circuits the conductors of the cable, the said member being of a length along the axis of the conductors equal at least to one quarter of the operating wave-length, means for varying the Tit high frequency current, in particular energytransmitting cables, comprising a member which short-circuits the said conductors at points located at nodes of the current flowing through said conductors and are of a length along the axis of the conductors equal at least to one quarter of the operating wave-length of the current flowing through saidconductors and means for varying the length of said member along the axis of the conductors in accordance with variations in the operating wave-length of the.current flowing through said conductors.

7. Apparatus for tuning concentric energytransmitting cables having an outer and a central conductor, comprising a hollow cylindrical member which is open at one end and which shortcircuits the outer and central conductors of the cable at points located at nodes of the current flowing through the conductors, the said member being or a length along the axis of the conductors equal at least to one-quarter of the op- 

